Korean Patent Application KR20090071275A discloses a drum type washing machine which includes a tub for washing clothes, a water supply pipe, a circulating pipe, a transfer pipe, a pump and a drain pipe. The water supply pipe is connected to the tub to supply water to the tub. The transfer pipe is connected to the tub to remove water from the tub. The pump is connected to the transfer pipe. The drain pipe is connected to the pump to discharge the water to a drain. The circulating pipe is connected to the pump to circulate the water back to the tub. A circulating valve and a drain valve are respectively arranged in the circulating pipe and the drain pipe. The pump is shared by the circulating pipe and the drain pipe but requires two valves to move the water in the correct direction.
The present invention aims to provide a centrifugal pump which is particularly suitable for the above application.